1. Field of the Invention
The present invention relates to a seat for vehicle use, the front portion of which is capable of tipping up.
2. Background Art
Conventionally, a tip-up seat, which is arranged in a rear seat of an automobile, has been put into practical use in which the front end portion of a seat cushion can be held at a tip-up position. In this type tip-up seat, the seat cushion is rotated to the tip-up position around the rear end of the seat cushion. Under the above condition, the whole seat is slid to the front. In this way, the volume of a baggage room can be extended and a large quantity of baggage can be loaded. In this connection, in general, when a distance from the floor of a vehicle to the seat face of a seat cushion is not sufficiently long, the thigh support function of supporting the knee of a passenger is lowered. Accordingly, there is a demand of enhancing the thigh support function so that the passenger can comfortably drive the vehicle.
In order to solve the above problems, Japanese Unexamined Patent Publication No. 11-91422 discloses the following technique. There is provided a seat cushion which is divided into two portions of a rear and a front cushion. The front cushion is capable of tipping up with respect to the rear cushion via a rock device, and the rear cushion is held on a base.
However, this technique is developed on the assumption that the space formed between the seat cushion and the seat back is used as a space into which baggage is put and no consideration is given to the thigh support function. Therefore, it is impossible for the above technique to meet the demand described above.
The present invention has been accomplished to solve the above problems. It is an object of the present invention to provide a seat for vehicle use characterized in that the thigh support function can be enhanced by utilizing a tip-up function of a simple structure.
A seat for vehicle use according to the invention comprises a seat back, a seat cushion, a tip-up unit which tips up a forward end side of the seat cushion from a base position to an upward tip-up position, and a rock unit which holds the seat cushion at a position between the base position and the tip-up position.
According to the invention, the seat cushion includes a front seat cushion positioned at a front side of a vehicle and a rear seat cushion positioned at the rear of the front seat cushion; and the front seat cushion is provided with the tip-up unit.
According to the invention, the longest distance in the longitudinal direction of the vehicle from the tip-up unit to the rear end portion of the front seat cushion is shorter than the distance in the vertical direction of the vehicle from the tip-up unit to a floor of the vehicle.
According to the invention, the boundary between the front seat cushion and the rear seat cushion is located in the vicinity of a portion right below the lower end portion of the seat back on the front side.
According to the invention, the rock unit permits a tip-up motion of the seat cushion in a direction to the tip-up position and restricts a tip-down motion of the seat cushion in a direction to the base position.
According to the invention, the rock unit includes a first gear and a second gear, the second gear fixed to the seat cushion; the second gear is capable of moving along the first gear according to the tip-up motion of the seat cushion while engaging with the first gear; and the first gear and the second gear are mutually engaged so as to restrict the tip-down motion of the seat cushion.
According to the invention, the rock unit is disposed at a position in the vehicle more forward than the position of the tip-up unit.
According to the invention, the rock unit includes a first gear and a second gear, the second gear fixed to the seat cushion; and the second gear is capable of moving along the first gear according to a movement of the seat cushion from the base position to the upward tip-up position while engaging with the first gear at a plurality of different positions.
According to the invention, the seat for vehicle use further comprises a disengagement unit for disengaging the first gear and the second gear.